Picture assembling apparatus for



. F. VON OKOLICSANYI Re. 20,311

PICTURE ASSEMBLING APPARATUS FOR TELEVISION RECEIVERS 7 3 9 1 3 2 m w MF l4"? 9/70/1125 an Original Filed July 7, 1932 Reissued Mar. 23, 1937 7R 20,311

UNITED STATES PATENT OFFICE PICTURE ASSEMBLING APPARATUS FOR TELEVISIONRECEIVERS Franz von Okolicsanyi, Nuremberg, Germany Original No.1,923,520, dated August 22, 1933, Serial No. 621,290, July 7, 1932, andin Germany June 2'7, 1931. Application for reissue August 10, 1935,Serial No. 35,676

5 Claims. 178-6) 'Picture assembling apparatus are known in If L and Bare equal, then the incident and rewhlch the assembling of the pictureis effected flected rays coincide with one another and the by means of anumber of mirror surfaces arangle which is enclosed by the outermostrays, ranged along a rotary axis and displaced through that is to say,the rays to the beginning and end 1 an angle relatively to one another,and used in of the lines isalso equal to the angle, and as conjunctionwith a linear source of light which can be seen directly from therectangular triis parallel to the axis of rotation, a mirror surangleswhich are produced, equal to face being associated with each pictureline. In b order that the assembling of the picture should I in beuniform and without gaps, the mirrors are uniformly distrib t d througha t t l angle of if, as is allowable in the case of small angles, the360", so that one revolution of the mirror screw angle is substitutedfor the sinus of the angle, formed by the said mirror surfaces causes ae get t complete picture to be assembled, the next picb I; turefollowing without any gap. If it is desired 2 to produce a very detailedpicture by using a very and large number of lines, it is necessary touse a 2 large number of mirror surfaces corresponding 1 b.Z

to the large number of lines so that the angle If this result iscompared with the equation 20 between the two mirrors becomes verysmall.

The great sharpness of the picture which is l thereby obtained has,however, a series of great B L b.Z disadvantages' it is found that thetwo are identical, since, in

If the picture is not to be distorted, the obser- View of the assumptionL can be substituted 5 vation distance and the distance between the for2:

mirror screw and the Source of light must not The following results canbe derived from the I be smailL It been found that the equation of themirror screw. As the number of servation distance B is dependent uponthe dlslines 2 increases tance L of the lamp, as well as upon the width1 b of the lines or mirrors, and the number Z of 30 the lines. If theobservation distance and the distance of the lamp are great relativelyto the becomes smaller,-that is to Say, F becomes greatwidth and heightof the picture, then a law simier, which means that the observationdistance as lar to the lens law well as the distance of the lamp must bein- 1 1 1 creased. As can be seen from the formula, an 35 A unfavourablygreat observation distance may be reduced by a corresponding increase inthe lamp holds goods. This is due to the fact that in the distance whichhas, however, other disadvantages. case of subjective observation of alinear source The light losses increase so that the brightness of lightarranged parallel to the axis of rotaof the picture is reduced. In orderthat light 40 tion, a surface of light is seen in the mirror screw. fromthe strip-like source of light should reach The screw thus actsoptically as a cylindrical the eye of the observer over the uppermostand mirror. The focus F has a value which depends lowermost mirror, thesource of light must, in acupon the width of the mirror and the numbercordance with the increased distance between the of mirrors, mirror andsource of light, be made longer. It 45 b.Z further follows from theformula, as in the case Zr of lenses, that the optical adjustment isalways more sensitive with respect to the shorter diswtnch can be testedas fonqws' when tance. In the case of small variations in the dismlrrorscrew i revolutlon (2K) Z lmes tance, the observer will thus see thepicture dis- 50 Pm seen' Qne lme 1s thtls completely seen dur torted.Therefore, in practice, the distance of mg a rotation of the mlrrorthrough an angle the lamp must be equal or smaller than the observationdistance.

a degrees= The present invention enables the distance of z the lamp andthe observation distance to be re- 55 duced to a very large extent bythe mirrors being subdivided, notwith respect to an angle 21, but withrespect to an angle 11.21, wherein n is an integer.

In the accompanying drawing Figures 1 and 2 illustrate diagrammaticallythe old and the new arrangement respectively. Figure 3 is a sideelevation partly in section of an arrangement including a coveringcylinder and drive means.

Figure 4 is a similar view of a modification.

As will be seen from the plan view, the mirror surfaces 2, 3, 4 aredisplaced relatively to one another through an equal angle. Let usassume that the mirror screw comprises 90 mirrors. In the oldarrangement, the angle between two consecutive mirrors is- 90 In thiscase the mirrors have a screwthread with steeply inclined pitch (Figure1).

In the arrangement according to the present invention the mirrors formtwo, three or more screwthreads, assuming the I dimensions of themirrors to be the same; for instance, in Figure 2, three screwthreadshave been shown, by way of example. The angle through which the seriesof mirrors are displaced relatively to one another is equal to Themirror screw for the picture of 90 lines thus appears to be composed ofthree simple mirror screws for 30 lines, with a correspondinglydecreased height. In any case the smallest observation distancecorresponds to a mirror screw of 30 lines.

If it is desired to maintain the same picture frequency per second, itis necessary, as can easily be seen, to cause the mirror screw to rotateat a speed which is three times greater. As each three mirrors now havethe same angular position along the whole of the screw mirror, it isnecessary always to cover two mirrors, in order to prevent thesimultaneous appearance of three picture elements. This is attainedaccording to another feature of the invention by means of a cylinderprovided with a helical slot and surrounding the mirror screw. One formof construction embodying'this feature is illustrated in Figures 3 and4. A triplicate screw is mounted on the spindle l, and is surrounded bya cylinder 5 which is provided with a single-thread helical slot 6, thewidth of which is equal to the pitch of the mirror screw. The cylinderrotates at a speed corresponding to the picture frequency, that is tosay, at a speed three times smaller than that of the mirror screw. Inthis way two-thirds of the mirror screw is always covered and each partthereof is left free once during each three revolutions of the mirrorscrew. In the construction illustrated in Figure 3, the two rotary partshave a common drive and the coupling between them is effected throughthe intermediary of toothed wheels 1, 8, 9, III geared together with asuitable gear ratio. It is to be understood that instead of the toothedwheels, use may be made of friction wheels.

According to another form of construction, the two rotary parts aredriven separately by means of synchronous motors. By using suitable numbers of pairs of poles corresponding to the num bers 'of revolutions,(as is well known, the product of pairs of poles and number ofrevolutions is constant) it is possible to drive the synchronous motorsfrom the same supply circuit.

The great advantage of the arrangement according to the inventionconsists in that it is possible to use small observation distances and.lamp distances and to obtain very bright pictures. It is also possibleto accommodate the mirror screw and the source of light in av commoncasing.

What I claim is:

1. An apparatus for the assembling of pictures in television reception,comprising a mirror screw consisting of a number of plates having mirroredges, thenumber of the said plates corresponding to the number ofpicture lines and all of them being superposed along a rotary axis andbeing distributed over several helical turns and means for rotating thesaid mirror screw in combination with a rotary screen consisting of acylinder adapted to be rotated at a slower speed than the mirror screwto uncover only one of the said plates with mirror edges lying in thesame angular position, for the purpose of direct observation of a linearsource of light.

2. An apparatus as claimed in claim 1, characterized in that the saidscreen in the form of a cylinder surrounds the mirror screw.

3. An apparatus as claimed in claim 1 and having means for rotating thescreen which are separate from the means for rotating the mirror screw.

4. An apparatus for the assembling of pictures in television receptioncomprising a rotatable mirror screw consisting of a number of plateshaving mirror edges of uniform length and uniformly spaced from the axisof rotation of the screw, the number of said plates corresponding to thenumber of picture lines and all of them being superposed along saidrotary axis and being distributed over several helical turns, and meansfor rotating said mirror screw in combination with a rotary screenconsisting of a cylinder adapted to be rotated at a slower speed thanthe mirror screw to uncover only one of said plates with mirror edgeslying in the same angular position, for the purpose of directobservation of a linear source of light.

5. An apparatus as claimed in claim 4, characterized in that the lengthof the mirror edges approximately corresponds to the diameter of themirror screw.

FRANZ VON OKOLICSANYI.

